Plaquette valence bond state in spin-1/2 J1-J2 XY model on square lattice

TL;DR

This paper investigates the ground state phases of the spin-1/2 J1-J2 XY model on a square lattice, identifying a plaquette valence bond phase between magnetic orders, and finds no evidence of a quantum spin liquid phase.

Contribution

The study reveals the existence of a plaquette valence bond phase in the J1-J2 XY model, contrasting with the Heisenberg model, using advanced DMRG techniques.

Findings

Plaquette valence bond phase exists between J2/J1 = 0.50 and 0.54.

No evidence of quantum spin liquid phase in the XY model.

Finite dimer orders characterize the plaquette phase.

Abstract

We studied the ground state phase diagram of spin-1/2 J1-J2 XY model on the square lattice with first- J1 and second-neighbor J2 antiferromagnetic interactions using both iDMRG and DMRG approaches. We show that a plaquette valence bond phase is realized in an intermediate region 0.50 <= J2/J1 <= 0.54 between a N\'eel magnetic ordered phase at J2/J1 < 0.50 and a stripy magnetic ordered phase at J2/J1 >= 0.54. The plaquette valence bond phase is characterized by finite dimer orders in both the horizontal and vertical directions. Contrary to the spin-1/2 J1-J2 Heisenberg model, we do not find numerical evidence for a quantum spin liquid phase in the J1-J2 XY model.